1. Field of the Invention
The present invention relates generally to a heat dissipation fan, and in particular to a heat dissipation fan having reduced turbulence induced in the back side of fan blades and enhancing protection of the blades.
2. The Related Art
Heat dissipation fans are commonly employed to enhance removal of heat generated in computers in order to maintain proper operation of the computers. A side-mount heat dissipation fan comprises a casing having an open top for intake of surrounding air and a side opening in communication with a heat sink to conduct air flow toward and through the heat sink. The casing has a bottom that is closed for supporting the fan blades thereon. Since the fan blades are rotated at a high speed, undesired impact of the fan blades with the bottom of the casing inevitably causes damage to the fan blades. To reduce the risk of impact, the fan blades are arranged at a sufficient distance from the bottom. This effectively overcomes the impact issue. However, a large gap is formed between the fan blades and the bottom of the casing, and air that is sucked into the fan in an axial direction may flow to the back side of the fan blades instead of being driven out of the fin along the side opening by centrifugal force. The air that flows to the back side of the fan blades induces turbulence that interferes with the air flowing toward the side opening and thus reducing the operation efficiency of the fan.
The present invention is thus aimed to overcome the problem caused by the back side turbulence of a side-mount heat dissipation fan.